Spinal Fixation Assembly

ABSTRACT

Disclosed herein are a spinal fixation assembly and method to provide adequate rigidity and support for a vertebral column without requiring additional pedicle screws and spinal rods. The spinal fixation assembly includes a spinal rod loop with multiple sides configured to be attached to a vertebral body with two or more pedicle screws. Each pedicle screw is adapted to fit at various locations along the spinal rod loop.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.16/870,273, filed on May 8, 2020, which is a continuation of U.S.application Ser. No. 15/649,903, filed on Jul. 14, 2017, which claimsthe benefit of the filing date of U.S. Provisional Patent ApplicationNo. 62/362,690, filed on Jul. 15, 2016, the disclosures of which arehereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an assembly and a method for spinalfixation, and in particular relates to a spinal rod and a method forspinal fixation configured to reduce the use of bone penetratingconnections and/or additional fixture devices.

Spinal rods are routinely used in spinal fusion procedures to treatdifferent spinal disorders, such as scoliosis, degenerative discdisease, disc herniation, spinal stenosis, or other abnormalities.Typically, such procedures involve properly aligning two or morevertebrae and permanently fusing them together through the use of two ormore pedicle screws attached by the spinal rods. This constructstabilizes the spine until fusion occurs.

Spinal rod fracture is the most common type of fixation device failurein spinal fusion procedures. Particularly in procedures such ascorrective osteotomy and long-segment spinal fusion, the risk of spinalrod failure can be significant. Spinal rod fractures occur because theimplanted spinal rod is unable to sustain the load long enough to allowthe vertebrae to fuse together. Rod failure generally does not occurover a single overloading event (shock loading), but instead occurs dueto fatigue over time. To prevent spinal rod failure, multiple spinalrods across the same vertebral bodies may be required. For example, whena single spinal rod is unable to provide the necessary support, multiplerods across the same vertebral bodies may be connected with additionalbone anchoring pedicle screws to provide additional rigidity.

A “quad rod” technique uses four rods instead of two rods across thevertebrae. A second rod is added to the main rod on each side of thespinous process and connected by rod-to-rod connectors to increaseoverall rigidity of the fixation assembly. However, the quad rodtechnique requires multiple rod-to-rod connectors to connect the firstand second rod to each other, which further complicates the spinalfusion surgery by adding additional surgery time and effort to locateand place connectors in narrow regions between screws and rods.Furthermore, the rod-to-rod connector connections at the spinal rodrepresent the weakest point of the spinal rod, and hence the area mostsusceptible to structural failure. The greater amount of connectionpoints lead to more potential rod failure points. Additional rodinterfaces, and rod-to-rod connectors may exacerbate the risk of stressrelated failure.

Therefore, there exists a need to provide a spinal fixation assembly andmethod that provides rigidity without requiring additional fixturedevices.

BRIEF SUMMARY OF THE INVENTION

Disclosed herein are spinal fixation assemblies and methods for spinalfixation configured to reduce the use of bone penetrating connectionsand/or additional fixture devices

In a first aspect of the present invention, a spinal fixation assemblyis provided. The spinal fixation assembly may include a first pediclescrew with a first channel and a second pedicle screw with a secondchannel. The spinal fixation assembly may have one or more loops. Eachloop may have a loop thickness and may be defined by a spinal rodthickness. The first and second channels may be at least as wide as thespinal rod thickness and narrower than the loop thickness.

In accordance with the first aspect, the first and second pedicle screwmay each include a bone portion and a tulip polyaxially moveable withrespect to the bone screw portion. The loop may be a closed loop. Theloop may be lemniscate shaped. The loop may include variable dimension.The loop may also have telescopic portions which may include a ladderportion for reinforcing the loop.

In other aspects, the loop may include first and second sides. The firstside may engage with the first pedicle screw and the second side mayengage with the second pedicle screw.

In a second aspect of the present invention, a spinal rod assembly isprovided. The spinal rod assembly may include a spinal rod, a spinal rodconnector, a first pedicle screw, a second pedicle screw and a thirdpedicle screw. The spinal rod connector may have connector rod which mayhave a coupling mechanism adapted to fit the spinal rod. The first andsecond pedicle screws may attach the spinal rod to a vertebral body. Thecoupling mechanism of the spinal rod connector may connect the spinalrod to the spinal rod connector. The third pedicle screw may connect theconnector rod to the vertebral body.

In accordance with the second aspect, the spinal rod may be a loop whichmay include one or more sides. The first and second pedicle screws mayattach to one loop side.

In a third aspect of the present invention, a spinal rod assembly isprovided. The spinal rod assembly may include a spinal rod, a spinal rodreinforcer, a first pedicle screw and a second pedicle screw. The spinalrod reinforcer may have one or more arms. Each arm may have a couplingmechanism adapted to fit the spinal rod. The first and second pediclescrew may attach the spinal rod to a vertebral body. The couplingmechanism of the spinal rod reinforcer may be attached to the spinalrod.

In accordance with the third aspect, the spinal rod loop may have one ormore sides. The first and second pedicle screws may be attached to oneloop side. One or more pedicle screws may attach the spinal rodreinforcer to the vertebral body.

In other aspects, at least two arms of the spinal rod reinforcer may beattached to opposite ends of a central portion of the spinal rodreinforcer. The spinal rod reinforcer may be substantially C-shaped. Thecentral portion of the spinal rod reinforcer may be substantiallyparallel to the spinal rod. The spinal rod reinforcer may be monolithic.

In a fourth aspect of the present invention, a spinal rod assembly isprovided. The spinal rod assembly may include a first spinal rod, asecond spinal rod, and a spinal rod connector. The spinal rod connectormay have a reinforcer component. The reinforcer component may beattached to the spinal rod connector by two arms. Two openings atopposite ends of the spinal rod connector may be provided to receive thefirst and second spinal rods. A length of the openings may be varied toadjust the placement of the spinal rods relative to the spinal rodconnector. Set screws may be used to secure spinal rods to spinal rodconnector. The spinal rod connector with the reinforcer component may bemonolithic.

A fifth aspect of the present invention is a method of securing a spinalfixation assembly having two pedicle screws and a spinal rod loop. Amethod in accordance with this aspect of the invention may include thesteps of inserting a first pedicle screw on a first vertebrae and asecond pedicle screw on a second vertebrae, connecting the first pediclescrew to a loop side of the spinal rod loop on the first vertebrae, andconnecting the second pedicle screw to the same loop side of the spinalrod loop on the second vertebrae. The second pedicle screw may beconnected to a second loop side of the spinal rod loop.

A sixth aspect of the present invention is a method of performing a quadrod procedure to attach a spinal rod reinforcer to a spinal rod. Amethod in accordance with this aspect of the invention may include thesteps of connecting a first arm of a spinal rod reinforcer to a firstlocation on the spinal rod, connecting a second arm of the spinal rodreinforcer to a second location on the spinal rod, inserting a pediclescrew on a vertebrae medially or laterally adjacent to the spinal rod,and connecting a central portion of a spinal rod reinforcer to thepedicle screw. The second pedicle screw may be inserted between thefirst and second location on the spinal rod.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the subject matter of the presentinvention and the various advantages thereof can be realized byreference to the following detailed description, in which reference ismade to the following accompanying drawings:

FIG. 1 is a perspective view of a spinal rod loop according to oneembodiment of the present invention.

FIG. 2 is a perspective view of the spinal rod loop of FIG. 1 andpedicle screw assembly connected to a vertebral column.

FIG. 3A is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 1 showing a first arrangement among the loop and pedicle screws.

FIG. 3B is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 1 showing a second arrangement among the loop and pediclescrews.

FIG. 3C is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 1 showing a third arrangement among the loop and pedicle screws.

FIG. 4 is a perspective view of a spinal rod loop according to anotherembodiment of the present invention.

FIG. 5 is an exploded view of a spinal rod loop of yet anotherembodiment of the present invention.

FIG. 6 is a perspective view of the spinal rod loop of FIG. 5 andpedicle screw assembly connected to a vertebral column.

FIG. 7A is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 5 showing a first arrangement among the loop and pedicle screws.

FIG. 7B is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 5 showing a second arrangement among the loop and pediclescrews.

FIG. 7C is a top view of the spinal rod loop and pedicle screw assemblyof FIG. 5 showing a third arrangement among the loop and pedicle screws.

FIG. 8 is a perspective view of a spinal rod connector with a firstcoupling mechanism according to one embodiment of the present invention.

FIG. 9A is a side view of a spinal rod connector according to anotherembodiment of the present invention.

FIG. 9B is a top view of the spinal rod connector of FIG. 9A

FIG. 10 is a top view of the spinal connector of FIG. 9A connected tothe spinal rod loop of FIG. 1.

FIG. 11 is a perspective view of a spinal rod reinforcer according toone embodiment of the present invention.

FIG. 12 is a top view of the spinal rod reinforcer of FIG. 11 connectedto a spinal rod loop.

FIG. 13A is a top view of a spinal rod reinforcer according to anotherembodiment of the present invention.

FIG. 13B is a top view of a spinal rod reinforcer according to yetanother embodiment of the present invention.

FIG. 14A is a perspective view of a spinal rod connector according toone embodiment of the present invention.

FIG. 14B is a top view of the spinal rod connector of FIG. 14A connectedto a first and a second spinal rod.

DETAILED DESCRIPTION

Referring to FIG. 1, shows a perspective view of an embodiment of aspinal rod loop 100 according to the present invention. Spinal rod loop100 comprises a first elliptical-shaped member 102 and an adjoiningsecond elliptical-shaped member 104. The loop has an upper superior side106, a lower inferior side 108, a medial side 110, and a lateral side112 enclosing an inner aperture 114. Spinal rod loop 100 also has ananterior surface 118 facing a vertebra, and an opposing posteriorsurface 120 facing away from the vertebra. The lemniscate-shaped spinalrod of this embodiment provides a significant increase in rigidity overa traditional spinal rod because the elliptical-shaped members of thisspinal rod loop allow for improved stress distribution. Consequently,the increased stiffness of this spinal rod will minimize deflection ormicromotion as compared to a single rod, which has been known toincrease chances of fusion.

FIG. 2 shows a perspective view of spinal rod loop 100 connected to twoadjacent vertebral segments of a vertebral column 10. Medial side 110 offirst elliptical-shaped member 102 is connected to a first pedicle screw120, and medial side 110 of second elliptical-shaped member 104 isconnected to a second pedicle screw 122. As shown, pedicle screw channel124 is slightly wider than the thickness of medial side 110 of spinalrod loop 100, so that the pedicle screw channel is adapted to couplewith one side of the spinal rod loop. In the embodiments shown, thethickness or diameter of the spinal rod loop 100 is 3.5-6.35 mm and thelength is at least approximately 30 mm. In other embodiments, the rodmay extend over multiple spinal levels and therefore will have multipleelliptical-shaped members. In this design, the length could be as muchas 860 mm. In still further embodiments, the individualelliptical-shaped members may not necessarily be of the same length. Thewidth of the spinal rod loop ranges between approximately 10-100 mm. Thedimensions of the spinal rod loop 100 are based on the levels of thevertebra that is being fixed, and therefore can widely vary.

The sides of spinal rod loop 100 provide multiple coupling locations forthe pedicle screws. FIG. 3A shows a first arrangement in which firstpedicle screw 120 and second pedicle screw 122 are coupled to medialside 110 of each elliptical-shaped member respectively. As shown, themedial sides of both elliptical-shaped members are along a commonlongitudinal axis L1 as both elliptical-shaped members are the same sizein this embodiment. In other embodiments, adjoining elliptical-shapedmembers may not be of similar size or shape, and consequently the medialsides of these members may not lie on a common longitudinal axis. Instill other embodiments, the length of the individual members may varybut all members may have the same width, and thereby the medial sides ofthese members may lie on a common longitudinal axis. FIG. 3B shows asecond arrangement of the pedicle screws where first pedicle screw 120is coupled with medial side 110 of first elliptical-shaped member 102,and second pedicle screw 122 is coupled with lateral side 112 of secondelliptical-shaped member 104. The pedicle screws in this arrangement aresituated along two different longitudinal axes L1 and L4. FIG. 3C showsa third arrangement of the pedicle screws where first pedicle screw 120is coupled with upper superior side 106, and second pedicle screw 122 iscoupled with lower inferior side 108. Thus, as shown in FIGS. 3A-C, themultiple sides of spinal loop rod 100 provide multiple locations forpedicle screw connections, thereby allowing increased flexibility toproperly locate and attach pedicle screws in different arrangements.Furthermore, spinal rod loop 100 provide the rigidity and support ofmultiple single rods but only requires two pedicle screws to properlysecure the spinal rod loop to the vertebral columns, thereby reducingthe number of bone anchoring penetrations required in the assembly.

Elliptical-shaped members 102, 104 shown in this first embodiment are ofthe same size and shape, however, other embodiments may have members ofdifferent sizes and shapes to vary the rigidity and connection locationsof the pedicle screws. For instance, it is contemplated to haverectangular-shaped portions forming loop 100 or the like. Furthermore,the members may be differently sized so that one member is larger thanthe other in length and or width. In still other embodiments, there maybe more than two members in the spinal rod loop. A number ofelliptical-shaped members can be connected or rod loops may be connectedin series as well.

In a method according to a further aspect of the present invention,spinal rod loop 100 is utilized with two pedicle screws (120,122) tofuse adjacent vertebral bodies. Although loop 100 may be utilized inmany types of surgeries, it is designed for use in situations wheremultiple spinal rods may have otherwise been employed, for instance,spinal osteotomy procedures like pedicle subtraction osteotomy. Whateverthe procedure, subsequent to implantation of two or more pedicle screwsloop 100 is placed in engagement with the pedicle screws, much like in atypical pedicle screw fusion procedure. However, the design of loop 100preferably provides a fixation with a strength approaching or evenexceeding that of a two rod construct provided in certain situations, asnoted above. The spinal rod may even span contralaterally weavingbetween a spinous processes (not shown).

FIG. 4 shows a perspective view of another embodiment of a spinal rodloop 200. Spinal rod loop 200 is similar to spinal rod loop 100, andtherefore like elements are referred to with similar reference numeralwithin the 200-series. For instance, spinal rod loop 200 includes firstand second elliptical-shaped members 202, 204. However, where thosemembers are directly attached to another in spinal rod loop 100, spinalrod loop 200 of this embodiment includes an additional connector element224 connecting the members. Connector element 224 may have a differentcross section, i.e., thicker or thinner than loop 200 thickness. Asshown in FIGS. 3A-C of spinal rod loop 100, pedicle screw locations andarrangements can similarly be varied for spinal rod loop 200.

FIG. 5 shows an exploded view of yet another embodiment of a spinal rodloop 400. The spinal rod loop according to this embodiment is a closedrectangular loop having an upper superior side 406, a lower inferiorside 408, a medial side 410, and a lateral side 412 enclosing an inneraperture 414. Spinal rod loop 400 also has an anterior surface 418facing a vertebra, and an opposing posterior surface 420 facing awayfrom the vertebra. Three cross beams 426 span the width between medialside 410 and lateral side 412 reinforcing spinal rod loop 400. Medialside 410 and lateral side 412 include telescopic members 428 that can beadjusted along longitudinal axes L6 and L7, respectively, to readilyvary the length of the spinal rod loop. Telescopic members 428 areslidably engaged with one another and are locked in place with thesuperior and inferior side of spinal rod loop 400 by tightening thepedicle screws. Medial side 410 and lateral side 412 have a slot 415adapted to receive cross beams 426. Cross beams 426 can be moved alongslot 415 and locked into desired position. The telescopic mechanism ofspinal rod loop 400 also allows for varying the rigidity of the spinalrod by adjusting the length. The spinal rod loop provides more rigidsupport when the sliding telescopic members are retracted, and lessrigid support when the telescopic members are extended. In otherembodiments, ends 406 and 408 may be welded to the medial and lateralsides. While three cross beams are shown in this embodiment, otherembodiments may have more or less than three cross beams.

FIG. 6 shows a perspective view of spinal rod loop 400 connected to twoadjacent vertebral segments of a vertebral column 10. A first pediclescrew 420 and a second pedicle screw 422 are connected to medial side410 of spinal rod loop 400. As shown, pedicle screw channel 424 isslightly wider than the thickness of medial side 410 of spinal rod loop400, so that the pedicle screw channel is adapted to couple with oneside of the spinal rod loop. Additionally, cross beams 426 areadjustable within slot 415 to allow for spinal rod loop 400 to fitwithin pedicle screw channel 424 and to avoid interfering with pediclescrews 420 and 422.

Similar to spinal rod loop 100, the sides of spinal rod loop 400 providemultiple coupling locations for the pedicle screws. FIG. 7A shows afirst arrangement in which first pedicle screw 420 and second pediclescrew 422 are coupled to medial side 410. In this arrangement, thepedicle screws lie along a common longitudinal axis L6. FIG. 7B shows asecond arrangement of the pedicle screws where first pedicle screw 420is coupled with lateral side 412, and second pedicle screw 422 iscoupled with the opposite medial side 410 of spinal rod loop 400. Thepedicle screws in this arrangement are on two different longitudinalaxes L6 and L7. FIG. 7C shows a third arrangement of the pedicle screwswhere first pedicle screw 420 is coupled with upper superior side 406and second pedicle screw 422 is coupled with lower inferior side 408 ofspinal rod loop 400. Thus, as illustrated in FIGS. 7A-C, the multiplesides of spinal loop rod 400 provide multiple locations for pediclescrew connections, thereby allowing increased flexibility to properlylocate and attach pedicle screws. Furthermore, the multiple sides ofspinal rod loop 400 provide the rigidity and support of multiple singlerods but only require two pedicle screws to properly secure the spinalrod loop to the vertebral column, thereby reducing the number of boneanchoring penetrations required in the assembly. All spinal rod loopembodiments disclosed herein may be preoperatively or operatively bentto conform to pedicle screw insertion locations and the required rodplacement on the spine. Spinal rod loops disclosed herein may be linkedto each other with the rod-to-rod connectors disclosed in U.S. patentapplication Ser. No. 15/606,279, the disclosure of which is herebyincorporated by reference herein.

FIG. 8 is a perspective view of a spinal rod connector 500 according toa first embodiment. Spinal rod connector 500 includes a connector rod502 with a coupling mechanism 504 on one end and a pedicle screw 506 onthe opposite end. Coupling mechanism 504 has a channel 508 adapted tocouple with a spinal rod 512. A set screw 510 secures the couplingmechanism 504 to spinal rod 512. Spinal rod connectors according to thisembodiment may generally range from 10 mm to 100 mm in length with athickness (diameter) of about 3.5 mm to 6.35 mm. Of course, as withother embodiments according to the present invention, these dimensionsmay vary widely depending upon the specific application.

FIGS. 9A and 9B show a spinal rod connector 600 with a second couplingmechanism 604. In this embodiment, a connector rod 602 attached tocoupling mechanism 604 can rotate about a longitudinal axis L9. Thisrotation allows connector rod 602 to be readily adjusted to align andconnect to a spinal rod 612.

FIG. 10 shows a top view of spinal rod connector 600 of FIG. 9Aconnected to spinal rod loop 100 of FIG. 1. Spinal rod loop 100 connectsa first vertebra 12 (via pedicle screw 120) to a second adjoiningvertebra 14 (via pedicle screw 122). As shown, coupling mechanism 604 ofspinal rod connector 600 is attached to lower inferior side 108 ofsecond elliptical-shaped member 104. Coupling mechanism 604 allows for180 degrees of rotation of spinal rod connector 600. The combined lengthof spinal rod connector 600 and spinal rod loop 100 shown in thisspecific embodiment may range from 45 mm to 860 mm. Spinal rod connectorthicknesses (diameter) may range from 3.5 mm to 6.35 mm. In otherembodiments, the coupling mechanism may be attached to other sides ofthe first or second elliptical member. In any event, because theopposite end of spinal rod connector 600 is anchored to a third vertebra16 (via a pedicle screw 606), the assembly allows three vertebrae to befused. Connector rod 602 can be rotated as shown in FIG. 9B to enableprecise positioning of the pedicle screw insertion. This can be ofconcern especially if the third vertebra 16 is a sacral bone.

In a method according to a further aspect of the present invention,spinal rod connector 600 is used in conjunction with spinal rod loop 100to fuse a third vertebra using only one pedicle screw 606. Spinal rodloop 100 is connected to first and second vertebra 14, 16 by a methodlike that described in paragraph [0029]. One end of the spinal rodconnector is then connected to spinal rod 100 by attaching couplingmechanism 604, and the other end is connected to pedicle screw 606 tocomplete the assembly. Of course, it is contemplated to utilizeconnector 600 in connection with any of the loops disclosed herein aswell as in connection with standard spinal rods.

FIG. 11 is a perspective view of a spinal rod reinforcer 700 accordingto a first embodiment of the present invention. Spinal rod reinforcer700 includes a connector rod 702 with three attached arms. A first arm704 is connected to one end of connector rod 702 with an adjustablescrew 710. Adjustable screw 710 allows first arm 704 to be rotated abouta longitudinal axis L10 and locked into position upon tightening. Anopposite end of first arm 704 has a coupling mechanism 714 with achannel 720 adapted to connect to a spinal rod 716. A set screw 718secures coupling mechanism 714 to spinal rod 716. In this embodiment,connector rod 702 is at least 30 mm long, and the width (length) of thethree attached arms may range from 10 mm to 100 mm. Thickness (diameter)of connector rod 702 and each arm may range from 3.5 mm to 6.35 mm.

Connector 702 also has a second fixed arm 706 including a similarcoupling mechanism 714 to connect with spinal rod 716. Finally,connector 702 includes a third arm 708 substantially similar to firstarm 704. In this embodiment, all three arms are of equal length andconnect to a spinal rod 716 running parallel to connector rod 702. Inother embodiments, however, the number of arms may vary and the armlengths of different arms may also vary to connect with spinal rods thatare not parallel to the connector rod. Likewise, it is contemplated toallow for arm 706 to rotate like arms 704 and 708.

FIG. 12 shows a top view of spinal rod reinforcer 700 of FIG. 11connected to a spinal rod loop 800 having three elliptical-shapedmembers. Spinal rod loop 800 connects a first vertebra 12, a secondvertebra 14, and a third vertebra 16. Pedicle screws 120, 122, and 124are attached to the first, second and the third elliptical-shapedmembers respectively. All three pedicle screws are attached to medialside 810 of each elliptical-shaped members of spinal rod loop 800 inthis embodiment. In other embodiments, pedicle screws can be connectedto different sides and in different arrangements across spinal rod loop800, as illustrated in FIGS. 3A-C.

The three coupling mechanisms of spinal rod reinforcer 700 are attachedto lateral side 812 of each elliptical-shaped member. In otherembodiments, the coupling mechanisms may be attached to other sides ofthe elliptical-shaped members. Adjustable screws 710 and 712 allow thefirst and second arm respectively of spinal rod reinforcer 700 to bereadily manipulated and connected to a spinal rod.

As illustrated in this figure, spinal rod reinforcer 700 can be attachedto reinforce an existing spinal rod loop 800 without requiring any boneanchoring insertions, whereas attaching a second spinal rod to providereinforcement will require at least two or more bone anchoringinsertions. This is made possible because the multiple sides of spinalrod loop 800 provide rigidity to take on additional loading, and alsoprovide multiple connection points to successfully couple a spinal rodwith a suitably adapted spinal rod reinforcer 700. It is alsocontemplated to utilize reinforce in connection with a standard straightspinal rod to provide additional stability. In this embodiment, thelength of the spinal rod loop and reinforcer may range from 45 mm to 860mm. The combined width, i.e., from medial side 810 of spinal rod loop800 to connector 702 may vary from 20 mm to 120 mm. The length of spinalrod reinforcer may range from 30 mm to 70 mm, with a thickness(diameter) of 3.5 mm to 6.5 mm.

In a method according to a further aspect of the present invention,spinal rod reinforcer 700 is used to reinforce spinal rod loop 800without requiring additional pedicle screws. Spinal rod loop 800 isconnected to first, second, and third vertebra 12, 14, 16, in aprocedure like that described in paragraph [0029]. Spinal rod reinforcer700 is then attached by connecting three coupling mechanisms 714, one toeach elliptical-shaped member of spinal rod loop 800. Thus, spinal rodreinforcement to an existing spinal rod is provided without the additionof bone penetrating connections. Of course, reinforce can be utilizedwith many different types of spinal rod constructs, including, but notlimited to, any of those disclosed herein.

Referring now to FIG. 13A, there is shown a spinal rod reinforcer 900according to another embodiment of the present invention. Spinal rodreinforcer 900 is a monolithic structure with a central portion 902 andtwo arms 905 that can be attached to spinal rod(s) 904 by connectors914. As used herein, the term “monolithic” is intended to meancomprising a substantially single body which, in some embodiments, maybe formed, composed or created spinal rod reinforcers without joints orseams and comprising substantially, but not necessarily rigid, uniformwhole. Spinal rod reinforcer 902 is pre-bent to align and connect withexisting spinal rod 904 to conform to pedicle screw insertion locationsand the required rod placement on the spine. Thereby, a surgeon mayreadily perform a quad rod technique by placing spinal rod reinforcer902 adjacent to an existing spinal rod (revision procedure) or a newlyimplanted spinal rod and attaching it with connectors 914. Pediclescrews 912 can be used to fix central portion 902 at suitable locationsalong the vertebral body (not shown).

Revision procedures are necessary when the spinal rod construct beginsto fail before the vertebral bodies fuse together. Replacing a failingspinal rod with a stronger rod construct, i.e., a thicker spinal rod, isgenerally not possible because the spinal fixation construct may becomemore prominent and may require new pedicle screws to accommodate thethicker spinal rod. Instead, surgeons may perform a quad rod techniquewhereby a second spinal rod is placed adjacent to and attached to anexisting spinal rod. However, the quad rod procedure is time andeffort-intensive requiring a surgeon, inter alia, to select a suitablesecond spinal rod, size the second spinal rod to match the existing rod,positioning and attaching the second spinal rod to the existing rod withrod connectors. Furthermore, the reinforcing spinal rod, i.e., thesecond spinal rod, must be suitably bent intra-operatively to configurethe shape of the second spinal rod to the implant location. Excessive orimproper bending may lead to weakening the second spinal rod andcomprise the spinal fixation assembly. The spinal rod reinforcers of thepresent invention may be provided in a kit having multiple spinal rodreinforcers in various pre-bent configurations and sizes to allow asurgeon to select a suitable reinforcer for specific patient needs.Therefore, a surgeon may readily perform a quad rod procedure byselecting a suitable spinal rod reinforcer to match patient-specificneeds pre-operatively or intra-operatively, and attaching the same to anexisting spinal rod with connectors 914. While the spinal rodreinforcers described in this embodiment are pre-bent and configured tobe used without any additional bending, other spinal reinforcers mayallow for minor shape changes to further tailor them to patient-specificneeds.

FIG. 13B shows a perspective view of another embodiment of a spinal rodreinforcer 1000. Spinal rod reinforcer 1000 is similar to spinal rodreinforcer 900, and therefore like elements are referred to with similarreference numerals within the 1000-series. For instance, spinal rodreinforcer 1000 includes a central portion 1002 and arms 1005. However,spinal rod reinforcer 1000 is generally C-shaped. Arms 1005 of spinalrod reinforcer 1000 sweep into central portion 1002 providing a largertransition area between the arms and the central portion andconsequently reducing stress risers in the transition areas. Theimproved rigidity and stress distribution properties allow spinal rod1000 to be implanted in confined implant locations or other quad rodprocedures requiring increased rod strengths. As more fully explainedabove, a spinal rod reinforcer kit having multiple spinal rodreinforcers 1000 in various configurations and shapes may be provided toallow a surgeon to make patient-specific selections. After selecting asuitable patient-specific spinal rod reinforcer 1000, the spinal rodreinforcer can be attached to spinal rod 1004 with connectors 1114.Central portion 1002 provides multiple locations to fix pedicle screws1110, 1112 to attach spinal rod reinforcer 1000 to a vertebral body (notshown). While two arms are shown in the preceding embodiments of spinalrod reinforcers 900, 1000, other embodiments may have only a single armor multiple arms connecting the central portion and the spinal rod.

FIGS. 14A and 14B show a spinal rod connector 1100 according to oneembodiment of the present invention. Spinal rod connector 1100 is amonolithic structure with a main body 1106 and a reinforcer portionhaving a reinforcer component 1118 substantially parallel to main body1106. Two arms 1116 connect main body 1106 to reinforcer component 1118.Arms 1116 transfer and distribute stress from main body 1106 toreinforcer component 1118 thereby strengthening spinal rod connector1100. Main body 1106 has a first opening 1108 at a proximal end and asecond opening 1110 at a distal end. Openings 1108 and 1110 areconfigured to receive a first spinal rod 1102 and a second spinal rod1104 respectively as best shown by directional arrows 1120 and 1122 inFIG. 14A. Set screws 1112 and 1114 can then be secured to holes 1124 and1126 respectively to secure first spinal rod 1102 and second spinal rod1114 to spinal rod connector 1100 as best shown in FIG. 14B. Otherembodiments may have locking pins, press-fitting, snap fitting, or othermeans to securely engage spinal rods with the spinal rod connector. Adepth D1 defining the length of openings 1108 and 1110 can be varied toadjust the rigidity of spinal rod connector 1106 and/or allow foradjusting spinal rod placement relative to the spinal rod connector. Forexample, increasing the length D1 of openings will allow greaterflexibility in spinal rod placement relative to the spinal rod connectorbut may reduce the rigidity of the spinal rod connector because of theloss of main body material. Alternatively, a single opening may extendthrough main body 1106 in other embodiments wherein main body 1106functions as a sleeve with an open interior passage.

Spinal rod connector 1110 can be used in pedicle subtraction osteotomyor corpectomy procedures wherein a surgeon can attach a first and asecond spinal rod with spinal rod connector 1110 by placing the spinalrod connector over the pedicle subtraction osteotomy or corpectomy site.As more fully discussed above, a suitable spinal rod connector may beselected to provide adequate rigidity and proper placement of spinalrods relative to the spinal rod connector based on patient-specificneeds. A spinal rod connector kit with multiple spinal rod connectorshaving different sizes and pre-bent shapes to match spine curvatures canbe provided to allow a surgeon to readily select the appropriate spinalrod connector. Spinal rod connectors may also be bent by the surgeoneither pre-operatively or intra-operatively to customize spinal rodconnectors to patient-specific needs. Spinal rod connectors can also beused in pediatric patients whereby a surgeon can adjust the relativeposition of spinal rod connector 1110 with spinal rods to account forthe patient's growth. Similarly, spinal rod connector may also be usedin revision procedures to strengthen and connect existing spinal rods oran existing spinal rod with a new spinal rod. While a spinal rodconnector with a reinforcer component is shown in FIGS. 14A and 14B,other embodiments may have spinal rod connectors without a reinforcercomponent thereby reducing their medial-lateral footprint and allowingthem to be used in constricted surgical sites. In other embodiments, thereinforcer component may be a separate construct that can be attached tothe spinal rod connector. While a reinforcer component with two arms areshown in FIGS. 14A and 14B, other embodiments may have only a single armor multiple arms connecting the main body to the reinforcer component.

While in the all the embodiments disclosed above, the spinal fixationassembly components comprise of rods, other embodiments may be made ofplates or other suitable elements. Spinal rod fixation components of thepresent disclosure may be made of a metal, polymers such aspolyetheretherketone (“PEEK”), carbon fiber reinforced PEEK, or othersuitable material such as ceramic, titanium ally, cobalt chrome, etc.,that is biocompatible and possess sufficient strength to resist damagefrom the compressive forces associated with attaching of conventionalbone screws to spinal rods. A combination of different material and/or acombination of flexible and reinforcing components to make spinal rodfixation components may also be used as described in U.S. Pat. Pub. No.2015/0216569, the disclosure of which is hereby incorporated byreference herein. Spinal rod fixation components of the presentinvention may be manufactured by machining, casting, forging, additivemanufacturing or other suitable methods. Spinal rod fixations elementsdisclosed herein may have a circular, rectangular, triangular, I-beam orany other suitable cross-section, or any combination thereof.

It is also to be understood that while dimensional ranges for variousembodiments are discussed above, the dimensions of embodiments accordingto the present invention may vary widely depending upon the particularapplication for which the embodiments are to be utilized. Thus,embodiments that fall outside of the specific ranges given herein areclearly contemplated, and the particular dimensions given here should betaken as merely exemplary.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A spinal rod assembly comprising: a spinal rod, a monolithic spinalrod reinforcer having two or more arms extending transverse to a mainbody, each arm having a coupling mechanism with first and secondcoupling channels adapted to receive the spinal rod, a first pediclescrew having a first channel; a second pedicle screw having a secondchannel, and a third pedicle screw having a third channel configured toattach the body of the spinal rod reinforcer to a vertebral body,wherein the first pedicle screw and the second pedicle screw areconfigured to attach the spinal rod to the vertebral body, and thecoupling mechanisms of the spinal rod reinforcer are attached to thespinal rod such that the spinal rod is received in the first and secondchannels and the first and second coupling channels.
 2. The spinal rodassembly of claim 1, wherein the two or more arms are attached toopposite ends of a central portion of the main body such that the spinalrod reinforcer is substantially C-shaped.
 3. The spinal rod assembly ofclaim 2, wherein the central portion is substantially parallel to thespinal rod.
 4. The spinal rod assembly of claim 1, wherein the spinalrod is a loop having one or more sides such that the first and secondpedicle screws attach to one loop side.
 5. A spinal rod assemblycomprising: first and second spinal rods, a monolithic spinal rodreinforcer comprising: a main body extending along a first direction,first and second arms extending away from the main body, and areinforcer body extending between the first and second arms along thefirst direction, wherein the main body includes a first opening toreceive the first spinal rod and a second opening to receive the secondspinal rod.
 6. The spinal rod assembly of claim 5, further including afirst pedicle screw having a first channel and a second pedicle screwhaving a second channel, wherein the first pedicle screw is configuredto attach the first spinal rod to a vertebral body and the secondpedicle screw is configured to attach the second spinal rod to thevertebral body.
 7. The spinal rod assembly of claim 6, further includingfirst and second fastening members, the first fastening memberconfigured to secure the first spinal rod to the main body and thesecond fastening member configured to secure the second spinal rod tothe main body.
 8. The spinal rod assembly of claim 7, wherein the firstfastening member is a set screw.
 9. The spinal rod assembly of claim 5,wherein the first opening defines a first depth and the second openingdefines a second depth.
 10. The spinal rod assembly of claim 9, whereinthe first depth is different from the second depth.
 11. A method forconnecting first and second spinal rods, the method comprising: placinga first spinal rod in a first opening of a main body of a monolithicspinal rod reinforcer, the main body extending along a first direction,the monolithic spinal rod reinforcer including a reinforcer bodyextending between first and second arms, and placing a second spinal rodin a second opening of the main body to connect the first spinal rod tothe second spinal rod.
 12. The method of claim 11, including steps of:inserting a first pedicle screw on a first vertebral body and a secondpedicle screw on a second vertebral body; connecting the first pediclescrew to the first spinal rod on the first vertebral body; andconnecting the second pedicle screw to the spinal rod on the secondvertebral body.
 13. The method of claim 11, wherein the step of placingthe first spinal rod includes placing the first spinal rod in the firstopening and securing the first spinal rod to the main body by afastening mechanism.
 14. The method of claim 13, wherein the fasteningmechanism includes a set screw.
 15. The method of claim 13, wherein thestep of placing the second spinal rod includes placing the second spinalrod in the second opening and securing the second spinal rod to the mainbody by a fastening mechanism.
 16. The method of claim 15, furtherincluding a step of connecting a third pedicle screw to the reinforcerbody.
 17. The method of claim 16, wherein the step of connecting thethird pedicle screw includes connecting the third pedicle screw to thefirst vertebral body.
 18. The method of claim 16, wherein the step ofconnecting the third pedicle screw includes connecting the third pediclescrew to the second vertebral body.